Safety ski binding



Feb. 21, 1967 H. MARKER 3,305,242

SAFETY SKI BINDING Filed June 22, 1964 2 Sheets-Sheet 1 Feb. 21, 1967 H.MARKER SAFETY SKI BINDING 2 Sheets-Sheet 2 Filed June 22, 1964 2a 21 2225 23 FIG 3 FIG. 4

United States Patent 3,305,242 SAFETY SK! BINDING Hannes Marker,Alpspitzstrasse 37, Garmisch-Partenkirchen, Germany Filed June 22, 1964,Ser. No. 376,774 8 Claims. (Cl. 280-11.35)

It is known to provide a safety ski binding, which comprises atightenable tension cable which is split adjacent to or behind the heel,and coupling elements for detachably connecting the ends of this cable,the coupling comprising a spring, which is subjected to the tension ofthe cable so that the interlocking members of the coupling elements arereleased when an adjustable spring deflection has been exceeded. Invarious embodiments of this known safety ski binding, the spring orsprings incorporated in the coupling have been designed to accomplishthe function of the springs which are arranged in the usual bindingsadjacent to the front tightener to ensure that the cable loop isresilient. In these embodiments of the known safety ski binding, thetension forces caused by the closing of the cable tightener and by thelifting of the heel of the boot during skiing are resiliently taken upadjacent to or behind the heel so that there is no move-ment of thecable relative to the down-pulls mounted on the side faces of the skibecause the cable may be non-resiliently connected to the fronttightener and the latter may be simple in structure and small in sizebecause the front tightener springs are eliminated.

The present invention relates to a further development and improvementof the known safety ski binding. According to the invention the lockingmember which is not subjected to the cable tension is movably connectedto the associated coupling element and is urged into its lockingposition by a spring device, which has a much lower strain resistance(spring rate) than the spring which is subjected to the cable tension.For this reason the coupling elements when released as a result of afall may be closed without need for straining either the spring orsprings which determine the resiliency of the cable loop, which springscan be strained only with difiiculty because they are necessarily verystrong, or for locking the one coupling element in the other byrelatively complicated means against any forward or rearward movement inthe longitudinal direction of the cable when the coupling is closed,bearing in mind that, in the latter case, an unintended opening of thecoupling will not be prevented when the cable is swung out of its normalposition. With the improvement according to the invention, only therelatively low strain resistance of the spring acting on the lockingmember which is not subjected to the cable tension must be overcome tomove the other locking member also into the locking position when it isdesired to close the coupling. The first-mentioned locking member willthen also return to the locking position. In this way the two couplingelements can be connected very easily and very reliably so that anunintended release of the two coupling elements is no longer possibleeven when the cable loop is relaxed.

In a safety ski binding according to the invention, in which at leastone cable end extends within a strong helical compression spring andbears on the rear end of this spring by means of a cable nipple, whichis connected to the locking member, which is movable under the action ofthe cable tension, whereas the front spring end in the closed portion ofthe coupling bears on a heel yoke, which is intended to engage the heelgroove of the skiing boot and is connected to the other cable end, afurther development of the invention resides in that the heel yokecomprises a hook for interengaging the front end of the spring, whichhook has a central opennig for the passage of the tension cable, theheel yoke having pivoted to 3,305,242 Patented Feb. 21, 1967 it, ifdesired, a locking member, which is urged by a spring into a lockingposition. In this embodiment, in which the direction of the cabletension coincides in a particularly favorable manner with the axialdirection of the compression spring surrounding the cable, one couplingelement is formed only by the helical compression spring itself, thecable end with the cable nipple, and the locking member secured to thecable nipple. Because the other locking member is movably attached tothe heel yoke and is resiliently urged to its locking position, it issufiicient to urge this locking member against the strain resistance ofits, closing sprnig out of the closing position when it is desired toclose the coupling elements until the front end of the strong helicalcompression spring has interengaged with the hook and is then retainedin this position by the spring-loaded locking member. The heel yoke mayhave a rearwardly directed, preferably framelike extension, which guideson each of its longitudinal sides a helical compression springsurrounding a cable end and which is provided on its transverse sidewith a keeper, which is movable against the force of a spring and formedwith an opening, into which a locking bolt screw-threaded in the cablenipple of the one cable end protrudes in the locking position. Thesymmetric spring arrangement, in which the direction of the cabletension and the spring axis coincide on each side, results in aparticularly suitable distribution of forces because a deflection of theforces which occur is no longer required in any case and the heel yokewith its extension guiding the springs is simply urged rearwardly whenthe heel lifts from the ski. The cooperation of the keeper with thelocking bolt of the one cable nipple results in a very simple andeifective locking device. The hook intended for interengaging with thefront end of the spring may be provided with an inclined run-up surfacefor the front end of the spring. This affords the advantage that it issufiicient to introduce the locking bolt into the opening of the keeperand then to push the front end of the spring over the run-up surfaceuntil this end is urged into the interengaging position with respect tothe hook under the action of the keeper on the rear end of the'spring.The keeper may extend on both sides beyond the transverse side of theextension of the heel yoke and may have a further opening, whichreceives a sliding bolt guiding the cable nipple of the non-detachablecable end. It is particularly desirable to urge the keeper against theextension of the heel yoke by a rubber spring, which is under the actionof a threaded bolt, which is screw-threaded in the framelike extensionand cooperates preferably with a pressure plate. According to theinvention, at least the detachable cable end may be urged outwardly withrespect to the axis of the compression spring associated with it by theeccentric guide face of the hook in the coupled position. Thisarrangement ensures that a release of the locking bolt by the opening ofthe keeper, resulting in a corresponding reduction of the length of thecompression spring under an excessively high tension, will reliablycause the compression spring to swing outwardly about its point ofengagement with the hook so that the spring clears the hook because thetension exerted by the tension cable has an outwardly directedcomponent. Finally, it is advantageous according to the invention if thecable nipples have a considerable length and an outer diameter which isalmost as large as the inside diameter of the compression springsbecause this arrangement ensures a good internal stiffening of thecompression springs at least in the rear portion whereas the outerguidance, as has already been mentioned, is effected by the framelikeextension of the heel yoke, which extension is provided withcorresponding concave side faces.

The invention will be explained more in detail in the followingdescription with reference to the drawing, which shows an embodiment byway of example. In the drawing FIG. 1 is a top plan view showing theillustrative embodiment of the coupling device according to theinvention with closed coupling elements,

FIG. 2 shows the coupling of FIG. 1 during the separation of thecoupling elements in response to a forward fall of the skier,

FIG. 3 shows the coupling element during the closing of the coupling andFIG. 4 is a transverse sectional view taken on line IVIV of FIG. 3, thecable ends and springs being omitted.

The heel yoke 1 for engaging the heel groove has a rearwardly directed,trapezoidal extension 2, which is framelike to reduce the weight and hasconcave longitudinal side portions 3 whereas the rear cross-piece 4- isprovided with a longitudinally extending, tapped bore and with a groove,which extends at right angles to the plane of the drawing and has anapproximately semicircular contour. The cable ends 5 and 6 are providedwith long, cylindrical cable nipples 7 and 8, which carry at their rearends spring cups 9 and 10 hearing on the rear ends of the strong helicalcompression springs 11 and 12.

The foremost turns of the compression springs 11 and 12 interengage withhooklike elevations 13 and 14- of the heel yoke 1. These hooklikeelevations formed adjacent to the ends of the heel yoke 1 and the endsof the heel yoke 1 are provided with cable guide slots 15 and 16 for thecable ends 5 and 6, which extend toward the center of the heel yoke 1only to such an extent that at least the cable end 5 is urged somewhatoutwardly relative to the center line of the helical compression spring11 so that the tension of the cable tends to swing the helical springoutwardly in the direction of the arrow 17 about the turn interengagedwith the hook 13. As is shown in FIG. 4, the hooked elevations 13 and 14are rounded to conform to the interior of the springs 11 and 12 and haveslightly inclined run-up surfaces 18 and 19.

A threaded bolt 20 is screw-threaded in the tapped bore of thecross-piece 4. The head of this bolt cooperates through the intermediaryof a pressure plate 21 with a padlike rubber spring 22, which urges thekeeper 23 against the rear face of the cross-piece 4. The keeper 23 hasat 24 a depression, which corresponds to the transverse groove of thecross-piece 4. Adjacent to this depression, the keeper has an opening,through which the threaded bolt 20 extends.

The cable nipple 7 carries a locking bolt 25, which is screw-threaded inan axial bore and the effective length of which can be varied byscrewing the bolt to any desired depth into the tapped axial bore of thecable nipple 7. The keeper 23 is provided with an elongated hole 26,through which the locking bolt protrudes in the locking position, as isshown in FIG. 1. On the other side of the cross-piece 4, the closingplate 23 is provided with another opening 27, in which a riveted Slidingbolt 28 is held to be axially non-displaceable but capable of a limitedpivotal movement. The sliding bolt 28 extends into an axial bore of thecable nipple 8 and guides the same during movements of the spring 12under the action of the cable tension. The sliding pin 28 is so longthat it does not leave the axial bore of the nipple 8 even in responseto the greatest reduction of the length of the spring 12 which may occurin practice.

The mode of operation of the cable coupling according to the inventionis apparent from FIGS. 2 and 3. FIG. 2 shows the coupling during itsrelease in response to an excessive tension force in the direction ofthe arrows 29 and 30. Depending on the depth to which the locking pin isscrewed into the cable nipple 7, the locking pin will disengage theelongated hole 26 after a shorter or longer deformation of the spring 11and the latter together with the cable end and the nipple will swingoutwardly under the action of the laterally outwardly directed componentof the force due to the cable tension about the fulcrum edge 31 providedbetween the runup surface 18 and the opening defined by the hooklikeprojection 13 and the concave wall surface 3. This fulcrum edge isparticularly apparent from FIG. 4. The foremost turn of the spring 11 isthus swung over the hook edge of the hook 13 so that the spring 11 withthe cable end 5 and the nipple 7 detaches completely from the heel yoke1 and its framelike extension 2.

FIG. 3 shows the described embodiment of the coupling device accordingto the invention during the closing of the two coupling elements whenthe same were released from each other in the manner just described. Forthis purpose, the locking pin 25 is initially introduced into theelongated hole 26 and pressure in the direction of the arrow 32 is thenexerted on the helical spring 11. As a result, the foremost turn of thehelical spring 11 in the longitudinal direction of the ski slides on therun-up surface and by means of the spring cup 9 urges the keeper 23upwardly. This results in a slight deformation of the rubber spring 22,as is apparent from FIG. 3. As the sliding bolt 28 is held in theopening 27 for a limited pivotal movement, it does not resist thetilting movement of the keeper 23. During this coupling operation, thespring 11 is not resiliently deformed because its strain resistance(spring rate) is much higher than that of the rubber spring 22 andbecause the spring 11 cannot be compressed at all by hand. As soon asthe foremost turn of the spring 11 has moved beyond the hook edge of thehook 13, the pressure of the rubber spring 22 urges the spring 11downwardly by means of the keeper 23 and the spring cup 9 so that thespring 11 is now in its coupling position whereas the keeper 23 hasreturned to its normal locking position.

I claim:

1. A safety ski binding comprising, in combination with two rearwardlyextending end portions of flexible tension cable adapted to be locatedon opposite sides of the heel of a ski boot, a yoke having a portion forengaging the heel of a ski boot, keeper member independent of cabletension movably connected to said yoke, coupling means for locking saidcable ends to said keeper member and for releasing one of said cableends in response to a predetermined tension exerted on said cable, saidcoupling means including a helical compression spring responsive to thetension in said cable mounted at each side of said yoke and mountedabout each of said cable ends, and resilient means for urging saidkeeper member into its locking position wherein it engages said couplingmeans, said resilient means having a lower spring resistance than saidhelical springs responsive to cable tension.

2. A safety ski binding as defined in claim 1 wherein said yoke includeshook portions formed on both sides of said heel engaging portion forinterengaging with the front end of said springs, a central opening ineach said hook for the passage of the tension cable therethrough, arearwardly extending portion having said keeper member resilientlymounted thereon, and guide means on the lateral sides of said rearwardlyextending portion for guiding said helical compression springs mountedon said cable ends.

3. A safety ski binding as defined in claim 2 wherein said couplingmeans further includes a nipple fastened to each of said cable ends,each of said nipples having a spring cup at its end for bearing on anend of said helical compression spring.

4. A safety ski binding as defined in claim 3 wherein said nippleconnected to the releasable cable has a screw threaded axial bore forcarrying a locking bolt therein, and said keeper has an aperture thereinfor receiving said locking bolt in a locked position.

5. A safety ski binding as defined in claim 4 wherein the effectivelength of said locking bolt is adjustable.

6. A safety ski binding as defined in claim 5 including a rivetedsliding bolt, said riveted sliding bolt extending through an axial holein the end of said other nipple and an aperture in said keeper so as toretain the cable end connected to said nipple in a non-detachablerelationship with said keeper.

7. A safety ski binding as defined in claim 2 wherein the openings inthe hooks for the passage of the cable ends are positioned so thattension on said cable tends to pivot the helical spring of saidreleasable cable end outwardly about its associated hook portion.

8. A safety ski binding as defined in claim 7 wherein said resilientmeans further provides the keeper with a tilting action so as to permitthe pivoting of the helical spring mounted on said releasable cable endso that the keeper member automatically returns to its locking positionin which it engages the coupling means of said releasable cable end.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCESMarker, German application Serial No. printed Feb. 9, 1961.

BENJAMIN HERSI-I, Primary Examiner.

MILTON L, SMITH, Examiner.

1. A SAFETY SKI BINDING COMPRISING, IN COMBINATION WITH TWO REARWARDLYEXTENDING END PORTIONS OF FLEXIBLE TENSION CABLE ADAPTED TO BE LOCATEDON OPPOSITE SIDES OF THE HEEL OF A SKI BOOT, A YOKE HAVING A PORTION FORENGAGING THE HEEL OF A SKI BOOT, KEEPER MEMBER INDEPENDENT OF CABLETENSION MOVABLY CONNECTED TO SAID YOKE, COUPLING MEANS FOR LOCKING SAIDCABLE ENDS TO SAID KEEPER MEMBER AND FOR RELEASING ONE OF SAID CABLEENDS IN RESPONSE TO A PREDETERMINED TENSION EXERTED ON SAID CABLE, SAIDCOUPLING MEANS INCLUDING A HELICAL COMPRESSION SPRING RESPONSIVE TO THETENSION IN SAID CABLE MOUNTED